<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    console.log( '123' );
    try {
        var e1 = new Error( '用户自己定义的异常对象' );
        throw e1;
    } catch ( e ) {
        console.log( e1 === e )
    }
    console.log( '456' );
</script>
</html>